Neuropsychological Correlates of Medication-Resistant Depression Among Adults at University of Ilorin Teaching Hospital, Kwara State

Treatment-resistant depression (TRD) presents complex clinical challenges, and neuropsychological profiling may reveal cognitive endophenotypes that explain poor medication response. This study examines neuropsychological correlates of TRD among adults attending the psychiatry outpatient clinic at University of Ilorin Teaching Hospital (UITH), Kwara State, North Central Nigeria. A case-control design will compare 60 patients with TRD against 60 treatment-responsive depressed patients and 60 healthy controls matched for age, gender, and education. The Cambridge Neuropsychological Test Automated Battery (CANTAB) will assess executive function, attention, memory, and psychomotor speed. Clinical variables including depression severity (MADRS), number of failed antidepressant trials, comorbid anxiety, and inflammatory markers (CRP, IL-6 from stored serum) will be collected. MANOVA and logistic regression analyses will identify neuropsychological variables that discriminate TRD from responsive depression. Emerging literature implicates frontostriatal dysfunction and elevated neuroinflammation in TRD, but Nigerian-based neuropsychological evidence is scarce. This study fills a critical regional gap, providing evidence that may inform neuromodulatory treatment selection, including transcranial direct current stimulation, for patients unresponsive to pharmacotherapy at UITH. Keywords: treatment-resistant depression, neuropsychology, CANTAB, Kwara State, neuromodulation